OLED Light Recycle Layer for Color Purity and Efficiency
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Solution Overview
Problem
Existing OLED display technologies face challenges in achieving both high photo-efficiency and color purity, particularly when incorporating quantum dots, as they often result in inefficient light conversion and color reproduction due to the random emission of light in all directions.
Innovation Solution
A display device structure is introduced, featuring a light recycle layer with specific transmittance properties for blue light and reflective properties for red and green light, combined with a color filter layer using quantum dots to convert blue light into red and green light, ensuring improved light directionality and color purity. This structure includes a slanted pixel define layer, an organic emission layer extending beyond the color filter layer, and a light recycle layer with a core-shell quantum dot configuration to enhance light recycling and conversion efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If quantum dots are incorporated into OLED display to improve color purity, then color purity is improved, but light conversion efficiency deteriorates due to random light emission in all directions
Solution Approach 1:
A light recycle layer is introduced as an intermediary component between the organic emission layer and color filter layer. This layer reflects light that would otherwise be lost, directing it back toward the color filter layer to improve light conversion efficiency while maintaining the quantum dot color filter's color purity enhancement function.
Solution Approach 2:
The patent recovers light that would normally be discarded or lost in the display structure. The light recycle layer captures and redirects light from the organic emission layer that misses the color filter layer, preventing energy waste and improving overall light conversion efficiency while preserving the color purity benefits of quantum dots.
2Use of energy by moving object
If the organic emission layer width is made longer than the color filter layer width, then light conversion efficiency is improved, but device complexity increases
Solution Approach 1:
The display device is segmented into distinct functional layers with clearly defined width relationships. The organic emission layer is designed with a larger width than the color filter layer, creating an overlapping structure that improves light conversion efficiency. This segmentation allows each layer to perform its specific function optimally without unnecessary complexity.
Solution Approach 2:
The patent addresses the width dimension relationship between layers to improve light conversion efficiency. By making the organic emission layer wider than the color filter layer in the horizontal dimension, more light from the emission layer can reach the color filter layer, improving efficiency without adding vertical complexity to the layer stack.
3Productivity
If a light recycle layer with specific transmittance properties is added, then photo-efficiency is improved, but device complexity increases
Solution Approach 1:
The light recycle layer serves as a mediator between the organic emission layer and color filter layer. It has specific transmittance properties that allow it to transmit useful light while reflecting light that would otherwise be lost, thereby improving photo-efficiency. This intermediary layer integrates smoothly into the existing layer structure without requiring fundamental redesign.
Solution Approach 2:
The light recycle layer is designed with specific optical parameters, particularly transmittance properties, that are optimized to improve photo-efficiency. By controlling the transmittance of this layer, the patent achieves better light management and photo-efficiency enhancement while maintaining a relatively simple additive layer structure.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The proposed structure significantly enhances photo-efficiency and color purity by effectively recycling and converting light, ensuring improved light directionality and color reproduction, while maintaining a cost-effective and simplified manufacturing process.
Implementation Method 1
a color filter layer using quantum dots to convert blue light into red and green light
Implementation Method 2
a light recycle layer with specific transmittance properties for blue light and reflective properties for red and green light
Data Source
AI summary
A display device includes a first electrode, a pixel define layer disposed on the first electrode, the pixel define layer including an opening, an organic emission layer disposed on the pixel define layer, the organic emission layer in electrical communication with the first electrode through the opening, a second electrode disposed on the organic emission layer, a light recycle layer disposed on the second electrode, and a color filter layer disposed on the light recycle layer, the color filter layer including a quantum dot, wherein a width of the organic emission layer is longer than a width of the color filter layer.